As one of the transition metal oxides, niobium pentoxide (Nb sub(2)O sub(5)) offers a broad variety of properties that make it a potentially useful and highly applicable material in many different ...areas. In comparison to many other transition metal oxides, Nb sub(2)O sub(5) has received relatively little attention, which presents a significant opportunity for future investigations aimed at fundamentally understanding this material and finding new and interesting applications for it. In this article, a general overview of Nb sub(2)O sub(5) is presented which focuses on its fundamental properties, synthesis methods and recent applications, along with a discussion on future research directions relevant to this material.
Short wave near infrared spectroscopy (NIR) method was used to detect the presence of lard adulteration in palm oil. MicroNIR was set up in two different scan modes to study the effect of path length ...to the performance of spectral measurement. Pure and adulterated palm oil sample were classified using soft independent modeling class analogy (SIMCA) algorithm with model accuracy more than 0.95 reported for both transflectance and transmission modes. Additionally, by employing partial least square (PLS) regression, the coefficient of determination (R2) of transflectance and transmission were 0.9987 and 0.9994 with root mean square error of calibration (RMSEC) of 0.5931 and 0.6703 respectively. In order to remove the uninformative variables, variable selection using cumulative adaptive reweighted sampling (CARS) has been performed. The result of R2 and RMSEC after variable selection for transflectance and transmission were improved significantly. Based on the result of classification and quantification analysis, the transmission mode has yield better prediction model compared to the transflectance mode to distinguish the pure and adulterated palm oil.
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•A new method to detect adulteration of lard in palm oil using portable NIR spectroscopy.•Transflectance and transmission modes were used to characterize the effect of path length via chemometrics.•The SIMCA was used for classification of pure and adulterated palm oil.•The PLS-R optimized by the CARS is employed to construct the quantification model.•The methodology proposed is portables, simple to implement and highly robust.
The oxides of copper (Cu x O) are fascinating materials due to their remarkable optical, electrical, thermal and magnetic properties. Nanostructuring of Cu x O can further enhance the performance of ...this important functional material and provide it with unique properties that do not exist in its bulk form. Three distinctly different phases of Cu x O, mainly CuO, Cu 2 O and Cu 4 O 3 , can be prepared by numerous synthesis techniques including, vapour deposition and liquid phase chemical methods. In this article, we present a review of nanostructured Cu x O focusing on their material properties, methods of synthesis and an overview of various applications that have been associated with nanostructured Cu x O.
In this paper, we present H2 gas sensors based on hollow and filled, well-aligned electrospun SnO2 nanofibers, operating at a low temperature of 150 °C. SnO2 nanofibers with diameters ranging from 80 ...to 400 nm have been successfully synthesized in which the diameter of the nanofibers can be controlled by adjusting the concentration of polyacrylonitrile in the solution for electrospinning. The presence of this polymer results in the formation of granular walls for the nanofibers. We discussed the correlation between nanofibers morphology, structure, oxygen vacancy contents and the gas sensing performances. X-ray photoelectron spectroscopy analysis revealed that the granular hollow SnO2 nanofibers, which show the highest responses, contain a significant number of oxygen vacancies, which are favorable for gas sensor operating at low temperatures.
With the world recovering from a public health disaster in the form of the COVID-19 pandemic and with political and social upheaval in the forms of wars such as in Ukraine and Sudan, localised ...fighting in various hotspots, the medical field faces huge challenges in addressing the needs of the various stakeholders. Still, these disasters represent opportunities to advance the new discoveries without compromising on the safety of the patients or general population. The COVID-19 vaccines were pushed through with great urgency driving on new discoveries of the genomic research, i.e. RNA based vaccines. This is complemented by the use of big data to monitor the disbursement of the vaccine to the general public. Unmistakably these new developments in tackling serious health disasters will lead to improvements on how the world tackle future crisis. Recent advances in artificial intelligence (AI), genomics discoveries and cell biology are driving research and fueling hope for the future. Amid this scenario of great upheavals and significant advances in technologies or emerging technologies for the health sector, SIRIM Berhad is increasing its preparedness in terms of development of new facilities and new competencies as well as building the platform for the communication of conventional health or medical technologies with other technologies particularly digital technologies to unlock the potential of emerging technologies in both medical and digital to develop novel solutions to future problems or challenges.
We report an efficient solar-light-driven photocatalyst based on three-dimensional nanoporous tungsten trioxide (WO3) films. These films are obtained by anodizing W foils in fluoride-containing ...electrolytes at room temperature and under low applied voltages with an efficient growth rate of 2μmh−1. The maximum thickness of the films is ~3μm that exceeds those of previously reported anodized WO3 films in fluoride-containing electrolytes. By investigating the photocatalytic properties of the films with thicknesses ranging from ~0.5 to ~3μm, the optimum thickness of the nanoporous film is found to be ~1μm, which demonstrates an impressive 120% improvement in the photocatalytic performance compared to that of a RF-sputtered nanotextured film with similar weights. We mainly ascribe this to large surface area and smaller bandgap.
► Anodized 3D nanoporous WO3 films were prepared at room temperature and under a low applied voltage. ► The thicknesses of the nanoporous WO3 films were up to ~3μm with a growth rate of ~2μmh−1. ► Field-assisted dissolution was the dominate mechanism to the formation of this 3D nanostructure. ► The crystal phase of the nanoporous film is orthorhombic with a relatively small bandgap of 2.73eV. ► The photocatalytic property of the nanoporous film shows 120% improvement compared to a sputtered film.
Highly ordered anodized Nb2O5 nanochannels are synthesized and utilized as the photoanodes for dye-sensitized solar cells (DSSCs). We characterize these DSSCs to determine the optimum photoanode ...thickness for the best cell performance. The samples with thicknesses from 5 to 25μm are obtained in glycerol based electrolyte at 180°C and their photoconversion properties are investigated utilizing various techniques including photocurrent–voltage characteristic, photovoltage decay and electrochemical impedance spectroscopy. Overall, the DSSC incorporating a 10μm thick Nb2O5 photoanode shows the highest efficiency of 4.48%. We analyze the factors that limit the efficiency of DSSCs.
•For the first time, highly ordered Nb2O5 nanochannels were used in DSSCs.•DSSCs with 10μm films had the best performance compared with other film thicknesses.•Thicker films decreased the electron lifetime and the charge transfer resistance.•More embedded impurities in thicker films hindered the performance of the DSSCs.
Two-dimensional (2D) molybdenum oxides at their various stoichiometries are promising candidates for generating plasmon resonances in visible light range. Herein, we demonstrate plasmonic 2D ...molybdenum oxide flakes for gas sensing applications, in which hydrogen (H2) is selected as a model gas. The 2D molybdenum oxide flakes are obtained using a grinding-assisted liquid exfoliation method and exposed to simulated sunlight to acquire its substoichiometric quasi-metallic form. After the exposure to H2 gas molecules, the quasi-metallic molybdenum oxide flakes are partially transformed into semiconducting states, thus gradually losing their plasmonic properties. The novel 2D plasmonic sensing platform is tested using different concentrations of H2 gas at various operating temperatures to comprehensively assess its sensing performance. The presented 2D plasmonic system offers great opportunities for future sensing and optical applications.
In this study, nanotubular structures were prepared on tantalum film via anodisation using an organic-based electrolyte. Nanotubular tantalum pentoxide (Ta
2
O
5
) was synthesised at 30 and 60 min ...and fabricated as a humidity sensor. The significant growth of anodised nanotubular Ta
2
O
5
has increased the number of pore structures and offered more water absorption active sites for humidity sensing detection. Both anodised samples were annealed to transform an amorphous structure to a cubic crystal structure, where the presence of more crystalline peaks was justified by the XRD spectra. The formation of pore size was proven by FESEM images and the density of pore distribution of the 60-min sensor was higher than the 30-min sensor with a diameter of 10–50 nm and 15–20 nm, respectively. Both fabricated sensors were tested for humidity detection in the range of 40–90% humidity level. Based on the results obtained, the 60-min sensor operated at 10 V possessed the highest sensitivity, low hysteresis, and improved stability compared to the 30-min sensor operated at the same bias voltage. Thus, this paper has elucidated the relationship of anodising time during nanostructure construction towards the variation of current output in humidity sensing due to the availability of oxygen vacancies and active sites as an effort to improve humidity sensing.
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